` A.P.3,8,13,18......` का कौन-सा पद 88 है?

Explanation

यहाँ ,a =3 ,
` d=8-3=13-8=5`
माना ` " " a_n =88`
` rArr " " 3+(n-1 )5 =88`
` rArr " " 3+5n -5 =88`
` rArr " " 5n -2 =88`
` rArr " " 5n =90 " " rArr " " n=18`
` therefore A.P.` का 18 वां पद 88 है|